聚合物溶液在驱油过程中对盲端类残余油的弹性作用

Elastic behavior of polymer solution to residual oil at dead-end

从微观驱油实验出发,研究了聚合物溶液的粘弹性对驱油效率的影响,定量分析了聚合物溶液的弹性在驱油过程中对残余油的作用机理。研究结果表明,对于油湿盲端,随着聚合物溶液弹性的增加,盲端类残余油的驱油效率提高。对于水湿“盲端”,聚合物溶液不能提高不可动残余油的驱替效率。如果“盲端”处的残余油为可动油,或有其他油滴流入“盲端”与残余油聚并,即可形成较大的可动油滴,用粘弹性流体驱替,可使“盲端”处残余油饱和度降低。对仿真类孔隙介质,聚合物溶液的粘弹性均可提高微观驱油效率。

The effects of viscoelastic behavior of polymer solution on oil displacement efficiency were studied. The action mechanism of elastic behavior of polymer solution in residual oil displacement at dead-ends was quantitatively analyzed. The investigation results indicate that the displacement efficiency of residual oil can be improved with increase in elastic behavior of polymer solution at oil-wet dead-ends, but the elastic behavior of polymer solution is impossible for non-movable oil at the water-wet dead-ends. If residual oil at dead-ends is movable, or other oil droplets flow into dead-ends and coalesce with residual oil, the bigger mobile oil drops can be formed. The viscoelastic fluid can be used to displace the residual oil and make the saturation of residual oil at dead-end reduce. For the emulated glass porous medium, the viscoelastic behavior of polymer solution can enhance the displacement efficiency.